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Characterization of CART neurons in the rat and human hypothalamus
- Source :
- The Journal of comparative neurology. 432(1)
- Publication Year :
- 2001
-
Abstract
- Cocaine- and amphetamine-regulated transcript (CART) is a recently described neuropeptide widely expressed in the rat brain. CART mRNA and peptides are found in hypothalamic sites such as the paraventricular nucleus (PVH), the supraoptic nucleus (SON), the lateral hypothalamic area (LHA), the dorsomedial nucleus of the hypothalamus (DMH), the arcuate nucleus (Arc), the periventricular nucleus (Pe), and the ventral premammillary nucleus (PMV). Intracerebroventricular administration of recombinant CART peptide decreases food intake and CART mRNA levels in the Arc are regulated by leptin. Leptin administration induces Fos expression in hypothalamic CART neurons in the PVH, the DMH, the Arc, and the PMV. In the current study, we used double label in situ hybridization histochemistry to investigate the potential direct action of leptin on hypothalamic CART neurons and to define the chemical identity of the hypothalamic CART neurons in the rat brain. We found that CART neurons in the Arc, DMH, and PMV express long form leptin-receptor mRNA, and the suppressor of cytokine signaling-3 (SOCS-3) mRNA after an acute dose of intravenous leptin. We also found that CART neurons in the parvicellular PVH, in the DMH and in the posterior Pe coexpress thyrotropin-releasing hormone (TRH) mRNA. CART neurons in the magnocellular PVH and in the SON coexpress dynorphin (DYN), and CART cell bodies in the LHA and in the posterior Pe coexpress melanin-concentrating hormone (MCH) and glutamic acid decarboxylase (GAD-67) mRNA. In the Arc, a few CART neurons coexpress neurotensin (NT) mRNA. In addition, we examined the distribution of CART immunoreactivity in the human hypothalamus. We found CART cell bodies in the PVH, in the SON, in the LHA, in the Arc (infundibular nucleus) and in the DMH. We also observed CART fibers throughout the hypothalamus, in the bed nucleus of the stria terminalis, and in the amygdala. Our results indicate that leptin directly acts on CART neurons in distinct nuclei of the rat hypothalamus. Furthermore, hypothalamic CART neurons coexpress neuropeptides involved in energy homeostasis, including MCH, TRH, DYN, and NT. The distribution of CART cell bodies and fibers in the human hypothalamus indicates that CART may also play a role in the regulation of energy homeostasis in humans.
- Subjects :
- Cart
Adult
Leptin
Male
endocrine system
medicine.medical_specialty
Transcription, Genetic
Hypothalamus
Neuropeptide
Nerve Tissue Proteins
Biology
Cocaine and amphetamine regulated transcript
Supraoptic nucleus
Rats, Sprague-Dawley
Species Specificity
immune system diseases
Internal medicine
medicine
Animals
Humans
RNA, Messenger
Aged
Injections, Intraventricular
Melanins
Neurons
Neurotransmitter Agents
Orexins
Leptin receptor
Hypothalamic Hormones
General Neuroscience
Neuropeptides
Intracellular Signaling Peptides and Proteins
virus diseases
Feeding Behavior
Middle Aged
Immunohistochemistry
Rats
Stria terminalis
Pituitary Hormones
Endocrinology
medicine.anatomical_structure
nervous system
Gene Expression Regulation
Organ Specificity
Protein Biosynthesis
Female
Periventricular nucleus
hormones, hormone substitutes, and hormone antagonists
Subjects
Details
- ISSN :
- 00219967
- Volume :
- 432
- Issue :
- 1
- Database :
- OpenAIRE
- Journal :
- The Journal of comparative neurology
- Accession number :
- edsair.doi.dedup.....feb413cb1033df899b0c665d23a58c62